Porsche tuning speedART PS9-300D Porsche Panamera Diesel The German tuners from speedART have developed an upgrade program for the Porsche Panamera Diesel. Dubbed the PS9-300D, they’ve managed to increase the output of the V6 3.0-liter engine to 296 hp (300 PS / 221 kW) and a peak torque of 479 lb.-ft (650 Nm), up from the [...]